PV Gap

Mary Said:

How does this solar charger work?

We Answered:

What is the input impedance of your voltmeter? You might be dropping some voltage while measuring it.

Try putting the solar cell to an op-amp circuit with a gain of 1, to prevent loading during measurement.

Henry Said:

Is SolarCity a trustworthy company?

We Answered:

interesting business model.
it's probably legit.

what happens is, if i'm an industrial electricity generator, the distributer will pay me $0.02 per kw.
if i'm a homeowner, they have to pay me $0.04 per kw.
so if i want to increase my payment, i make the deal that you describe.

i see 2 problems.
1. what happens if they go out of business?
2. what happens if the solar panels fail after 5 years.

other than that, and the obvious -- they make holes in your roof that leak, or the panels blow off in a windstorm and damage someone else's house, it seems okay to me.
if they're doing several in town, and they are a scam, it shouldn't take long for it to make the evening news.

Rene Said:

Which of the following describes the use of a renewable energy source?

We Answered:

Renewable energy is energy that can be used over and over again without the depletion of the source. B, C, and D all describe the burning of fossil fuels. Fossil fuels as an energy source takes many, many years to replenish, so they cannot be used over and over again without depletion; therefore fossil fuels are not renewable energy sources. Solar cells use the sun light for power, and since sun light will keep coming to Earth for a couple more millions of years, it is a renewable energy source. The answer is A.